In a 2G/3G mobile packet network architecture under a traditional 3rd generation partnership project (3GPP) specification, network elements such as a serving GPRS support node (SGSN) and a gateway GPRS support node (GGSN) and the like are both responsible for processing various signaling and responsible for forwarding data. But in general, a universal computing platform is more suitable for processing control plane signaling, such as a mobility management, a session management and the like, and a dedicated hardware platform is very strong in processing a performance of user plane data forwarding, but the signaling processing performance is relatively weak. Therefore, in order to improve the user data forwarding throughput to the maximum, a gateway such as a GGSN or the like generally adopts a dedicated hardware platform. The SGSN is focused on processing control plane signaling and generally adopts the universal computing platform, which has a strong ability to process signaling and has a weak ability to forward data. Once user data traffic increases quickly, a capacity of the SGSN needs to be continually expanded or the number of the SGSNs needs to be greatly increased, thus the cost is very high.
To solve the above-mentioned technical problem, a decoupling of control and forwarding is proposed in the development process of a 3GPP mobile broadband network architecture. After being decoupled, a control plane and a forwarding plane may be upgraded and expanded independently, the control plane may be deployed and maintained centrally, and the forwarding plane may be distributed and deployed to optimize route. In R8 stage of a 3GPP standard version, a brand new system architecture evolution (SAE) network is developed, and the system architecture thereof is as shown in FIG. 1, wherein an evolved universal terrestrial radio access network (E-UTRAN) achieves all functions related to radio access of the evolution network, a mobility management entity (MME) is responsible for the mobility management of the control plane, including user context and mobile state management. A serving gateway S-GW is a user plane anchor point between 3GPP access networks and terminates an E-TURAN interface. A packet data network gateway (P-GW) is a user plane anchor point between a 3GPP access network and a non-3GPP access network and is an interface of an external PDN packet data network. A home subscriber server (HSS) stores user subscription information. The MME, the S-GW, the P-GW and the home subscriber server (HSS) constitute a core network, which is referred to as an evolved packet core (EPC). In the SAE architecture, the MME only needs to process the control plane signaling, the S-GW and the P-GW are mainly responsible for forwarding user plane data. The S-GW and the P-GW may be combined into a network element, which is generally referred to as a gateway.
With the development of a mobile internet service, an enrichment of an enterprise network service and an integration of a mobile access network with a variety of systems, a gateway device needs to gradually develop towards more sophisticated service control and charging on the basis of the completion of a basic data forwarding function, in order to support the implementation and control of more abundant services of an operator. But in the SAE architecture, the gateway still needs to keep a large number of external signaling interfaces. The large number of external signaling interfaces of the gateway will bring a large amount of interface signaling, and the signaling processing performance of a gateway using the dedicated hardware platform is not strong, which is liable to become a bottleneck. In order to process a large amount of interface signaling, the gateway is bound to increase a large amount of hardware on the basis of the dedicated hardware platform, such as a computing processor chip or the like, such that the hardware platform of the gateway device is very complicated and too high in cost, which is not conducive to the promotion and deployment of a mobile packet data network.
To solve the processing bottleneck problem of the gateway signaling processing, in the prior art, it is proposed that an interface signaling processing function and a user plane data forwarding function of the gateway are separated. The interface signaling processing function is deployed on a universal computing platform to become a control plane device, and the user plane data forwarding function is deployed on a dedicated hardware platform to become a forwarding plane device. The control plane device processes an external signaling interaction, including general packet radio service tunnellinging protocol-control (GTP-C) signaling with the MME and signaling with other network elements, such as signaling with an AAA (Authentication, Authorization, Accounting) server, policy and charging control (PCC) signaling with a policy and charging rules function (PCRF), etc. After finishing a signaling consultation, the control plane device forwards information (referred to as forwarding context) needed by the forwarding plane device for forwarding a data message to the forwarding plane device, and the forwarding plane device forwards a user data message according to context information indicated by the control plane device.
Taking a general packet radio service tunnelling protocol (GTP) bearer establishment in the case of 3GPP access under the SAE architecture as an example, since the principle that the signaling is processed by the control plane device is abided, the technical problem of the abovementioned control and forwarding decoupled solution of the existing gateway lie in that all GTP-C signaling for establishing a forwarding plane GTP bearer is processed by the control plane device, and a forwarding plane internet protocol (IP), a GTP tunnel end identifier (TEID) and a circuit switched identifier (CSID) are all allocated by the control plane, this will bring the following defects.
1) The control plane device has no idea about a load sharing relationship of internal processing units of the forwarding plane device or a mapping relationship of the forwarding plane IP and TEID and GTP protocol processing units in the forwarding plane device, so direct allocation of the control plane device will lead to a load imbalance of each GTP protocol processing unit of the forwarding plane device.
2) The control plane device allocates the forwarding plane IP and the TEID. When one forwarding plane device is controlled by multiple control plane devices, it may need to avoid a conflict between the multiple control plane devices, so that the implementation is complicated.
3) The forwarding plane device is a large-capacity device and still has a local failure condition, in the prior art, in a case that a local failure occurs in the forwarding plane device, the control plane device may be only notified by a large amount of signaling to delete GTP bearers influenced by the failure, and the control plane device notifies other network elements of deleting these GTP bearers through signaling one by one, thus generating a large amount of control signaling.